CN1980100B - Real-time continuous wide-band wire-less transmitting detection method and apparatus - Google Patents

Abstract

The present invention provides a real-time and continuous broadband wireless propagation testing method and device, which down-converts the radio frequency CW signal to an intermediate frequency, performs high-speed sampling on the signal after detection and processing to obtain field strength distribution data, and synchronously collects GPS data at test points . Combine the field strength data of all test points with GPS data for statistical analysis, which can be used for wireless propagation characteristic statistics and channel model correction. Wherein said acquisition controller is a multi-thread acquisition controller, and the multi-thread work mode guarantees synchronous acquisition of the field strength signal output by the high-speed acquisition device and the GPS positioning information output by the GPS receiver device, and the two acquisition processes do not interfere with each other and are carried out synchronously . This design solves the difficulty of high-speed sampling and real-time recording of CW wave wireless signals. It solves the problem of synchronizing the collection of field strength signals and the collection of GPS geographic information of test points in the wireless signal propagation test under mobile conditions. The continuous acquisition of field strength data is realized.

Description

Real-time continuous broadband wireless propagation test method and device

technical field

The invention relates to the testing field of wireless communication, in particular to a test device capable of completing the collection of original signals of wireless propagation fading test effects, storage, statistical distribution analysis and display of field strength coverage effects, and a propagation test method using the test system.

Background technique

In the wireless propagation test, the basic measurement method should be able to timely and accurately measure, record and analyze the received real-time signals and their changes. Therefore, the test method must meet the following requirements: 1. The power of the transmitting antenna is known, and the measured The time remains constant; 2. The test antenna must be able to receive all target signals from the receiving antenna.

At present, there are corresponding drive test coverage equipment for mature standards of mobile communication systems such as GSM, WCDMA, and CDMA2000 to meet the needs of access network optimization. The air interface monitoring in the drive test process mainly intercepts the information of the air interface by means of existing standard test instruments and test software to achieve the purpose of obtaining test data. However, for these mature drive test coverage equipment, the base station transmits a signal with a certain modulation mode, and its transmission power changes from time to time, which cannot guarantee the condition of "the signal remains constant within the measurement time". Moreover, the current drive test systems are all aimed at mature standards such as GSM, WCDMA, and CDMA2000. The wireless frequency bands tested are fixed and cannot be applied to wireless signal propagation tests and model corrections in other frequency bands. Using existing instruments, such as spectrum analyzers, field strength meters, etc., although it is possible to test the field strength of wireless signals within a wide frequency range, the tester can only manually configure the screen and read the test value through the instrument screen. The process is time-consuming and labor-intensive, prone to human error, and the massive test results can only be analyzed after all tests are completed, so real-time testing cannot be realized.

In short, there is still a lack of a test system that can flexibly adjust the test frequency point within a wide frequency range, collect wireless signals in real time, continuously and at high speed, and record GPS information at the test point at the same time. Such a test system plays an important role in the propagation model test and correction of the future mobile communication system, as well as the coverage and optimization of the future wireless communication network.

Contents of the invention

The technical problem to be solved by the present invention is to provide a real-time continuous broadband wireless propagation test method and device, which obtains the field strength distribution data by down-converting the radio frequency CW signal to an intermediate frequency, and sampling the signal at high speed after detection processing, and synchronously Collect GPS data for test points. Combine the field strength data of all test points with GPS data for statistical analysis, which can be used for wireless propagation characteristic statistics and channel model correction.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A real-time continuous broadband wireless propagation test device, including a remote transmitting device and a receiving device, wherein the remote transmitting device includes a radio frequency CW wave generator for radio frequency CW wave emission;

The receiving equipment includes:

Down-conversion device: used to down-convert the radio frequency CW wave radio frequency signal received by the antenna to the intermediate frequency band;

Intermediate frequency envelope detection device: perform envelope detection processing on the CW signal in the intermediate frequency band;

High-speed data acquisition device: The high-speed acquisition device performs high-speed sampling on the output signal after detection, and outputs it through the high-speed data transmission interface after A/D conversion;

GPS receiving device: receive GPS satellite positioning information and output GPS positioning information;

Acquisition controller: The acquisition controller is used to configure the down-conversion device and the intermediate frequency envelope detection device, collect the signal output by the high-speed acquisition device and save the signal, and simultaneously collect and save the GPS information data output by the GPS receiving device.

As an improvement of the device of the present invention, the acquisition controller is a multi-thread acquisition controller, which executes concurrent field strength signal high-speed acquisition threads and GPS signal reading threads; synchronously collects the signals output by the high-speed acquisition device and the GPS receiving device Output GPS positioning information. The two acquisition processes do not interfere with each other and are carried out synchronously.

Wherein, the high-speed data transmission interface may adopt a 1394 bus interface. The GPS output interface can adopt RS232 serial interface.

Correspondingly, the present invention also provides a kind of real-time continuous broadband wireless propagation test method, comprising the steps of:

Step 1, the remote transmitting device transmits radio frequency CW waves;

Step 2. The test terminal receives the radio frequency CW wave, and down-converts the received radio frequency CW wave signal to an intermediate frequency band;

Step 3, performing envelope detection processing on the CW signal in the intermediate frequency band;

Step 4, performing high-speed sampling on the output signal after detection, and outputting it through a high-speed data transmission interface after A/D conversion;

Step 5, collecting GPS geographic information and outputting GPS information;

Step 6. Synchronously collect the output information of Step 4 and Step 5 and save it.

As an improvement of the method of the present invention, the method of synchronous acquisition in step 6 is: execute concurrent field strength signal high-speed acquisition thread and GPS signal reading thread; synchronous continuous acquisition step 4 and step 5 output information.

As a preferred method of the inventive method, the acquisition interval of high-speed sampling in the step 4 is 10ms, and the acquisition and output frequency of the GPS information in the step 5 is 1 time per second, that is, the selected GPS device is fixedly 1 output per second.

Simultaneously, after said step 6, a pair of stored information is also included to perform data processing steps, specifically as follows:

Step (1), mapping field strength information to GPS information;

Step (2), performing field strength distribution statistics, grouping the tested field strength information to obtain mean and variance;

Step (3), drawing according to the corresponding GPS information, drawing a wireless coverage trend diagram;

Step (4), perform statistics on the fading characteristics of the wireless signal, and bring the test results into the theoretical formula of wireless propagation for model correction.

Wherein, the calculation method of the mean value in the step (2) may be averaging over the spatial distance of 40 wavelengths to obtain the mean value envelope. The method of field strength distribution statistics may be to divide the field strength of all collection points into 5 grades, respectively count the percentages of the collection points in these 5 categories to the total number of points, and express it in the form of a histogram. The method of drawing the wireless coverage trend map in the step (3) can be combined with the electronic map, corresponding to each collection point, find out the corresponding plot point position on the electronic map according to the latitude and longitude, and mark the intensity value with different color fields.

The real-time continuous broadband wireless propagation testing method and device of the present invention have the following advantages:

First, according to the test requirements of Lee’s law (Lee’scriterion), for a carrier of a certain frequency band, it is required to test at least 50 points for averaging at a distance of 40 wavelengths in order to obtain the local sampling average. This design solves the difficulty of high-speed sampling and real-time recording of CW wave wireless signals.

Second, it solves the problem of synchronizing the collection of field strength signals and the collection of GPS geographic information of test points in the wireless signal propagation test under mobile conditions.

Third, the field strength for testing a certain frequency point can be set within a certain wide frequency range.

Fourth, the test process can realize the continuous collection of field strength data.

Fifth, realize the rapid acquisition of field strength signals by configuring the A/D conversion rate of the high-speed acquisition device, the depth of the FIFO, and the configuration of the high-speed transmission bus.

Description of drawings

FIG. 1 is a schematic structural diagram of a real-time continuous broadband wireless propagation testing device of the present invention.

Fig. 2 is a flow chart of data collection of the real-time continuous broadband wireless propagation testing device of the present invention.

Fig. 3 is a flow chart of a processing method of test data obtained by the real-time continuous broadband wireless propagation test device or test method of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a real-time continuous broadband wireless propagation test device includes remote transmitting equipment and receiving equipment. device, wherein the frequency and power of the radio frequency CW wave can be set by the user;

The receiving equipment includes:

Test vehicle: The receiving end of the remote station needs a specially equipped vehicle. The test antenna and GPS antenna must be placed on the roof of the vehicle. The test antenna is an omnidirectional antenna to ensure the reception quality of wireless signals and satellite signals; the following receiving equipment in the car,

Down-conversion device: used to down-convert the radio frequency CW wave radio frequency signal received by the antenna to the intermediate frequency band;

Intermediate frequency envelope detection device: perform envelope detection processing on the CW signal in the intermediate frequency band;

High-speed data acquisition device: The high-speed acquisition device performs high-speed sampling on the output signal after detection; after A/D conversion, it passes through the high-speed data transmission interface and then outputs through the 1394 bus;

GPS receiving device: collect GPS satellite positioning information (mainly latitude and longitude information), and output GPS positioning information through the serial interface;

Multi-thread acquisition controller: The acquisition controller is used to configure the down-conversion device and the intermediate frequency envelope detection device, and execute concurrent high-speed acquisition threads of field strength signals and GPS signal reading threads; synchronously collect the signals output by the high-speed acquisition device and the output of the GPS receiver device GPS positioning information data, and save it.

The radio frequency signal is collected at high speed. In this embodiment, it is set to a collection interval of 10ms, while the GPS device outputs GPS positioning information once per second, and the collection of these two signals is controlled by the collection controller to control the high-speed data collection device. It is realized by reading the information output by the GPS output interface. The GPS output interface can use RS232 serial interface.

In the example of the test device, multi-threading technology is preferably used to realize the synchronization of the two signal acquisition processes, so as to ensure that the field strength information, that is, the radio frequency signal received by the antenna at the receiving end, can correspond to the GPS information. The synchronization of the two is realized by configuring the multi-threading technology in the acquisition controller, wherein the multi-threading technology distributes the processor time to multiple sections of executable codes (called threads), thereby providing a multi-tasking processing function. Each thread is allocated processing time based on factors such as the thread's priority, the time elapsed since the thread was last run, and so on. Multi-threading technology can make full use of processors and improve system performance during time-consuming work (such as operating devices with slow reading speeds). The high-speed acquisition process of the field strength signal and the acquisition of GPS data are realized through different threads, and the two threads are carried out in parallel without interfering with each other, but the startup of the two threads is realized through the same trigger source, thus ensuring two The acquisition process starts and proceeds synchronously. The acquisition controller configures the preparation status of the high-speed data acquisition device through the high-speed data bus, starts the A/D conversion, ends the A/D conversion, and stores the data. The GPS device actively outputs GPS information. What the acquisition controller executes is to read GPS information.

The configuration and acquisition process of the above test device are shown in Figure 2, including the following parts:

1) The user inputs the configuration parameters of the down-conversion device, the intermediate frequency envelope detection device, and the high-speed data acquisition device through the human-computer interaction interface. The configuration parameters include the center frequency point of the down-conversion device, the output gain of the intermediate frequency envelope detection device, etc. The parameters are determined according to the frequency point of the specific test and the size of the signal power;

2) The multi-thread acquisition controller configures the down-conversion device, the intermediate frequency envelope detection device, and the high-speed data acquisition device according to the user input parameters;

3) The multi-thread acquisition controller configures the serial interface parameters of the GPS receiving device, including configuring the serial port number, baud rate, stop bit, check digit, etc., and the GPS receiving device outputs GPS positioning information through the serial interface;

4) The multi-threaded acquisition controller is configured as a multi-threaded working mode. When the acquisition program is executed, the concurrent high-speed acquisition thread of field strength signal and GPS signal reading thread are executed; the instantaneous field strength value and GPS positioning information of frequency points are collected synchronously and continuously, and the information is stored in the cache. Wherein the cache device can be arranged inside the acquisition controller, for example, it can be realized by using an SDRAM storage device with a fast reading speed;

5) After the collection is completed, save the collected data to disk.

A real-time continuous broadband wireless propagation test method, comprising the steps of:

Step 1, the remote transmitting device transmits radio frequency CW waves;

Step 2. The test terminal receives the radio frequency CW wave, and down-converts the received CW wave radio frequency signal to an intermediate frequency band;

Step 3, performing envelope detection processing on the CW signal in the intermediate frequency band;

Step 4, performing high-speed sampling on the output signal after detection, and outputting it through a high-speed data transmission interface after A/D conversion;

Step 5, collecting GPS geographic information and outputting GPS information;

Step 6. Synchronously collect the output information of Step 4 and Step 5 and save it.

Wherein, the method of synchronous acquisition in step 6 is: execute concurrent high-speed acquisition thread of field strength signal and GPS signal reading thread; and output information in step 4 and step 5 of synchronous continuous acquisition.

Wherein, the collection interval of the high-speed sampling in the step 4 is 10 ms, and the collection and output frequency of the GPS information in the step 5 is 1 time per second.

Wherein, after the step 6, a pair of stored information is also included to process the data, and its flow is shown in Figure 3, including the following steps:

Step (1), the field strength information is mapped to GPS information; the field strength data list is combined with the GPS data list, and the field strength data grouping is mapped to GPS data;

In step (2), the mean value and variance of the mean value of each group of data are calculated respectively, the field strength distribution statistics are performed, and the field strength information tested is grouped. Wherein, the calculation method of the mean value may be to take an average over the spatial distance of 40 wavelengths to obtain the mean value envelope. This system is called the local mean value, which is relative to the mean value on a specific location; the method of field strength distribution statistics can be to divide the field strength of all collection points into 5 grades, and count the collection in these 5 categories respectively Points as a percentage of the total points, expressed in a histogram.

Step (3), drawing according to the corresponding GPS information, drawing a wireless coverage trend map; that is, taking the longitude and latitude of the GPS as coordinates, and drawing the coverage trend with the average field strength mapping chromaticity. In this way, the coverage along the test route can be drawn on the electronic map, the points with weak field strength coverage can be found, and the reason for the signal power reduction can be analyzed according to the recorded geographical environment for network optimization analysis;

Step (4), performing statistics on the fading characteristics of the wireless signal, and describing the scene, bringing the test results into the theoretical formula of wireless propagation to correct the propagation model. Among them, the statistics of wireless signal fading characteristics include statistics on the distribution of the mean and variance of m groups and the statistics of the overall field strength fading distribution, and draw distribution histograms respectively; the statistics of wireless signal fading characteristics can be based on the test requirements of wireless signal fading characteristics, due to the high-speed acquisition device The acquisition interval can be configured as 10ms, so the maximum number of acquisition points per second can reach 100. With a speed of 20km/h, the mobile test vehicle can reach the jump area and weak signal area for detailed testing with an accuracy of 18 test points per meter. Taking the 3.5GHz signal as an example, the number of collection points within an intrinsic length of 40 wavelengths is 62, which can achieve the purpose of statistics on the fading distribution characteristics of wireless signals.

Claims (9)

1. the wide-band wire-less transmitting testing apparatus of a real-time continuous comprises far-end transmitter and receiving equipment, it is characterized in that:

Described far-end transmitter comprises radio frequency CW wave producer, is used for the emission of radio frequency CW ripple;

Described receiving equipment comprises:

Down-conversion device: the radio frequency CW ripple radiofrequency signal that is used for antenna is received is down-converted to mf band;

Intermediate frequency envelop detection apparatus: will carry out envelope detection at the radio frequency CW of mf band signal and handle;

High-speed data acquiring device: high-speed data acquiring device to detection after output signal carry out high-speed sampling, after A/D conversion, export through high speed data transmission interface;

GPS receiving system: receive the gps satellite locating information and export the GPS locating information;

Acquisition controller: acquisition controller is used to dispose down-conversion device and intermediate frequency envelop detection apparatus, gather the signal of high-speed data acquiring device output and preserve signal, and the GPS information data of synchronous acquisition GPS receiving system output and preservation, wherein, described acquisition controller is a multithreading acquisition controller, and the field intensity signal high speed acquisition thread and the gps signal of execution concurrence read thread; The GPS locating information of the signal of synchronous acquisition high-speed data acquiring device output and the output of GPS receiving system.

2. the wide-band wire-less transmitting testing apparatus of a kind of real-time continuous according to claim 1, it is characterized in that: described high speed data transmission interface is 1394 bus interface.

3. the wide-band wire-less transmitting testing apparatus of a kind of real-time continuous according to claim 1, it is characterized in that: the output interface of described GPS receiving system is the RS232 serial line interface.

4. the wide-band wire-less transmitting detection method of a real-time continuous is characterized in that comprising with step:

Step 1, far-end transmitter emission radio frequency CW ripple;

Step 2, test lead received RF CW ripple are down-converted to mf band with the CW ripple radiofrequency signal that receives;

Step 3, will carry out envelope detection at the CW of mf band signal and handle;

Step 4, output signal after the detection is carried out high-speed sampling, after the A/D conversion, export through high speed data transmission interface;

Step 5, collection gps satellite locating information are also exported the GPS locating information;

Step 6, synchronous acquisition step 4 and step 5 output information are also preserved, and wherein, the method for synchronous acquisition is: the field intensity signal high speed acquisition thread and the gps signal of execution concurrence read thread; Synchronous continuous acquisition step 4 and step 5 output information.

5. the wide-band wire-less transmitting detection method of a kind of real-time continuous according to claim 4 is characterized in that: the acquisition interval of described step 4 high speed sampling is 10ms, and the collection of GPS information and output frequency are each second 1 time in the described step 5.

6. the wide-band wire-less transmitting detection method of a kind of real-time continuous according to claim 4 is characterized in that: comprise also after the described step 6 that the information of a pair of preservation carries out the step of data processing, specific as follows:

Step (1), with the field intensity information mapping to GPS information;

Step (2), the field strength distribution statistics of carrying out are carried out packet transaction with the field intensity information of test, obtain average and variance;

Step (3), draw, draw the wireless coverage tendency chart according to the GPS information of correspondence;

Step (4), carry out wireless signal decline characteristic statistics, the result of test is brought into carry out the model correction in the radio transmission theoretical formula.

7. the wide-band wire-less transmitting detection method of a kind of real-time continuous according to claim 6 is characterized in that: the computational methods of average are in the described step (2): be averaged on the space length of 40 wavelength, to obtain the average envelope.

8. the wide-band wire-less transmitting detection method of a kind of real-time continuous according to claim 6, it is characterized in that: the method for field intensity distribution statistics is in the described step (2): the field intensity of all collection points is divided into 5 grades, adds up collection in these 5 grades respectively and count and account for the percentage of always counting.

9. the wide-band wire-less transmitting detection method of a kind of real-time continuous according to claim 6, it is characterized in that: the method for drawing the wireless coverage tendency chart in the described step (3) is, combine with electronic chart, corresponding each collection point, on electronic chart, find out corresponding described point position according to longitude and latitude, with different colours mark field intensity value.

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